1. Field of the Invention
The present invention relates to a method and apparatus for packaging articles in clear plastic packages, and more particularly to method and apparatus for sealing articles in card backed card and blister packages sealed with UV-curable adhesive.
2. Description of the Prior Art
The so-called xe2x80x9ccard and blisterxe2x80x9d type package has been used extensively for packaging small articles in a form that seals yet displays the article for the benefit of purchasers in a retail environment. Such a conventional card and blister package comprises a clear plastic portion that has a pre-formed cavity for holding an article(s), and a generally flat outer perimeter flange-like portion. A rectangular card of chipboard, or the like, appreciably larger than the card and blister piece, has printing on one or both of its sides, and one side is coated with heat-activated adhesive.
Conventional packaging techniques involve supporting a number of card and blister pieces on a segment of a rotary work table or xe2x80x9clazy Susanxe2x80x9d, loading the card and blister cavities with the article(s) to be packaged, placing the adhesive-coated surfaces of the cards into contact with the card and blister flanges. Then the packages are moved to a station where a hot plate is pressed into the backs of the cards to activate the heat activatable adhesive. Equipment for producing such packages requires a fair amount of special tooling, and is complex, energy-consumptive and expensive. The necessary time for heating and cooling limits productivity, and heat dissipation is a concern to be addressed. There appear to be additional limitations effecting productivity, inherent in the rotary work table type configurations.
In view of the foregoing it is a general object of the present invention to provide an improved method for packaging items in card and blister type packages.
Another object is to provide a simple yet effective packaging apparatus that can be commercially available at a lower price than conventional card and blister packaging technology.
A further object is to provide a packaging method with improved productivity.
Yet another object is to provide apparatus and method using UV light for packaging articles in card and blister type packages.
A further object is to provide an energy-efficient packaging method that does not involve application of heat.
These and other objects and advantages are provided by a method for packaging articles in card and blister-type packages and involves providing UV-transparent means on the outer surface of a UV light-porous conveyor belt, for supporting a plurality of plastic card and blister pieces against downward and lateral movement with their cavities facing upwards. The conveyor has a forward, intermediate, and a rearward part, and at the forward part articles are loaded within the card and blister cavities, then liquid UV-light curable adhesive is applied along the flanges of the card and blister pieces, or to a pertinent surface of the card. The method includes placing and positioning a printed card in contact with the flange of each card and blister piece and then advancing the supported packages to a UV illumination station at the intermediate part of the conveyor where the cards are pressed downwardly into contact with the flanges of the card and blister piece as UV exposure instantly cures the adhesive.
In one preferred embodiment of the invention the downward pressure is provided by rollers, and in another embodiment, downwardly directed air jets are used. Illumination is from UV light directed upwardly through the conveyor belt upper flight and through the UV transparent holders. The conveyor will then advance the sealed packages to the rear part of the conveyor, and around the conveyor end whereby the holders are inverted allowing gravity to cause the packages to drop from the holders for collection and further processing for shipment.